Name: Pickled Walnuts
Ingredients: unripe walnuts; coarse sea salt; vinegar; long pepper; capsicum; ginger; mustard seed; mace; pimento

Why it works: Pepper and capsicum match in chemistry and in kitchens. They rank in the top 2% of all ingredient pairs, and cooks put them together in 34,571 recipes. Both carry 2-isopropyl-3-methoxypyrazine, which smells earthy, pea. The science ↓

Pickled Walnuts

Ingredients

Directions

Run a large needle through each walnut in several places.
Soak the walnuts in a strong brine of coarse sea salt for 10 to 12 days.
Decant the brine and transfer the walnuts to a stone jar.
Heat vinegar nearly to boiling and pour it over the walnuts to cover them.
Simmer long pepper, capsicum, ginger, mustard seed, mace, and pimento with the vinegar for a few minutes.
Let the walnuts sit for about six months before using.

Recipe from a historical cookbook (Internet Archive).

Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.

Explore the science

The flavor team

The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.

Pepper + capsicumtop 2% of all pairs

Smell alikestrong

Cooked together34,571 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Walnut + capsicumtop 6% of all pairs

Smell alikestrong

Cooked together1,113 recipes

Shared aroma: 3-ethyl-2,5-dimethylpyrazine (roasted, nutty).
Vinegar + mustardtop 7% of all pairs

Smell alikemoderate

Cooked together14,067 recipes

Shared aroma: isobutyraldehyde (malty, green).
Capsicum + mustardtop 7% of all pairs

Smell alikestrong

Cooked together6,274 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).
Capsicum + gingertop 8% of all pairs

Smell alikemoderate

Cooked together3,890 recipes

Shared aroma: 2-isopropyl-3-methoxypyrazine (earthy, pea).

Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs

Swap the mace

How well each one fits the dish's main ingredients (walnut, vinegar, pepper, capsicum, ginger, mustard):

Allspicefits better
Turmericfits better
Tarragonfits better
Macethe original

Fit is the average pairing score against walnut, vinegar, pepper, capsicum, ginger, mustard. Candidates are from the same food group and used in at least 100 recipes.